In many instances, it is necessary for a physician to obtain a sample of endometrial tissue from a patient. For example, endometrial samples are taken for the detection of endometrial carcinoma or precancerous conditions. Endometrial tissue is also sampled to determine response to hormone therapy and in connection with the diagnosis of pathology associated with infertility. Endometrial tissue samples are obtained by scraping the uterine wall and aspirating the removed tissue. U.S. Pat. No. 4,935,003 discloses an aspiration tip configured to be connected to an external suction source. The tip is primarily used for performing suction abortions, but may also be employed to collect endometrial samples. The tip is relatively large, as is the volume of tissue collected thereby. In most instances, a relatively small tissue sample will suffice, and in order to minimize patient discomfort it is usually desirable to employ a less invasive device.
A number of relatively small diameter self-contained aspirator devices are known in the prior art. U.S. Pat. No. 5,069,224 discloses an endometrial aspirator which is representative of those previously employed. The aspirator of the '224 Patent comprises a tube having a closed end and a side opening near the closed end for the collection of tissue. A piston is disposed in the tube and is moved along the length of the tube to create a suction which draws tissue into the opening. The aspirator is moved about in the uterus and the combination of suction and the scraping effect of the opening draws tissue into the bore of the tube. The closed end requires that the tube be cut in order to permit ejection of the tissue sample therefrom. Cutting involves an extra step, which it would be desirable to eliminate. Even more significantly, the closed end design of the prior art aspirator results in a loss of tissue sample, since some portion of the sample will always remain in the tip when it is cut away. The lost tissue represents a sample collected from a specific portion of the uterus, and in some instances, may be of critical importance. In any instance, the lost sample constitutes a decrease the net volume of tissue available for analysis, and it is clearly desirable to avoid such loss.
In some instances, difficulties are encountered in inserting prior art aspirators through the cervix. This problem often occurs when cervical stenosis is present and generally necessitates the use of a cervical dilator to locate and open the cervical os prior to insertion of the aspirator. Use of a dilator necessitates an extra step in the sampling procedure and requires the physician to stock additional supplies. Elimination of a separate dilation step is clearly desirable. Cervical stenosis is a fairly common condition and is generally the result of injury or previous surgical procedures; hence, cervical dilation is frequently required, and presently employed aspirators are very often supplied along with a separate dilator.
It will be appreciated from the foregoing that there is a need for a device for obtaining samples of endometrial tissue which minimizes the impact of the procedure on the patient, and which permits the utilization of the full volume of the collected sample. Ideally, the sample should be fully discharged from the aspirator without cutting. It is further desirable that the sampler is capable of being utilized in those instances where cervical stenosis is present without requiring any additional dilation steps and/or the use of extraneous instrumentation.
The present invention provides a self-contained aspirator device which is capable of functioning as its own cervical dilator. The device enables the ready collection and discharge of the entirety of an endometrial tissue sample in a single process. These and other advantages of the present invention will be readily apparent from the drawings, discussion and description which follow.